Prime Rib Gravy - Drinkable Prime Rib!

I never met a gravy or a sauce I didn't like...most are easy and delicious! Here is a beef gravy made from the bones of a standing rib roast (often called a prime rib). Each cut of meat tastes differently, so I like gravy with my prime rib that actually tastes like prime rib. I use an au jus for the prime rib itself, usually with a horseradish cream sauce. How do you make prime rib or beef gravy?